docs: def delete(ctx, slot, force):
      """
      Deletes the configuration of a slot.
      """
      controller = ctx.obj['controller']
      if not force and not controller.slot_status[slot - 1]:
          ctx.fail('Not possible to delete an empty slot.')
      force or click.confirm(
          'Do you really want to delete'
          ' the configuration of slot {}?'.format(slot), abort=True, err=True)
      click.echo('Deleting the configuration of slot {}...'.format(slot))
      try:
          controller.zap_slot(slot)
      except YkpersError as e:
          _failed_to_write_msg(ctx, e)